1. Field of the Invention
The present invention relates to a tape recorder such as a video tape recorder (VTR) and a camcorder, which records and reproduces data with respect to a magnetic tape running along a predetermined path defined in a deck, and more particularly, to a tape loading device for a tape recorder which takes magnetic tape from the tape cassette in loading to bring the magnetic tape to a close contact with a head drum.
2. Description of the Related Art
FIG. 1 shows a moving deck 100 which is generally employed in a camcorder, as an example of a moving deck used in a conventional tape recorder. Referring to FIG. 1, the moving deck 100 of the conventional tape recorder includes a main chassis 110, a sub chassis 120 and a tape loading device.
The main chassis 110 forms a bottom of the moving deck 100, on which various components such as a head drum 130, a loading motor 150 and a capstan motor 140 are mounted.
The sub chassis 120 is slidably mounted on the main chassis 110, and reciprocates along the main chassis 110 during loading/unloading of the magnetic tape.
When loading a magnetic tape (not shown), the tape loading device takes the magnetic tape from a tape cassette (not shown) which is inserted in the moving deck 100, brings the magnetic tape into close contact with the head drum 130 and guides the magnetic tape so that the magnetic tape can run in close contact with the head drum 130. The tape loading device includes a pole base assembly 160, and stationary and movable guide rails 181, 185.
The pole base assembly 160 is mounted on the moving deck 100 to be moved with the loading/unloading of the magnetic tape, and guides the magnetic tape so that the magnetic tape runs in close contact with the head drum 130. Generally, there are a pair of pole base assemblies 160 in the moving deck 100, each being moved by the pressing of a link member 268 (FIG. 3) which is moved in association with the loading motor 150.
The guide rails 181, 185 guide the movement of the pole base assembly 160. More specifically, the guide rails 181, 185 include a pair of stationary guide rails 181, provided to the main chassis 120, and a pair of movable guide rails 185, provided to the sub chassis 120. The stationary and movable guide rails 181, 185 are inter-locked with each other by the movement of the sub chassis 120 during the loading of the magnetic tape, to form a movement path for the pole base assembly 160.
In the conventional moving deck 100 as shown in FIG. 1, a head drum base 170, which is mounted on the main chassis 110 to secure the head drum 130 with respect to the main chassis 110, is integrally formed with the guide rails 181. The movable guide rails 185 are integrally formed with the sub chassis 120.
FIG. 2 shows another moving deck 200, more recently introduced, in which the head drum base 170 (FIG. 1) is omitted from the tape recorder for the purpose of compactness and light-weight of the product, and the head drum 130 is directly mounted on the main chassis 210. In this construction, the stationary guide rails 281 are formed by bending a portion of the main chassis 210. The sub-chassis 220, which requires less strength than the main chassis 210, is formed of a plate which is thinner than the main chassis 210. Accordingly, the stationary guide rails 281 become thicker than the movable guide rails 285. In this configuration as shown in FIG. 3, a stepped portion (t) is defined at the connecting part between the stationary and movable guide rails 281, 285. Accordingly, during the loading of the magnetic tape, the pole base assembly 260 is obstructed by the stepped portion (t) in its movement from the movable guide rails 285 toward the stationary guide rails 281.
With the completion of the loading of the magnetic tape, the pole base assembly 260 is moved by the tension of the magnetic tape running in the deck 200. In order to avoid the movement of the pole base assembly 260, the pole base assembly 260 is biased in the ‘A’ direction by the link member 268 even after the completion of the magnetic tape loading. As the pole base assembly 260 is urged by the link member 268 at the time that the loading of the magnetic tape is completed, a moment to pivot the pole base assembly 260 in the ‘B’ direction of FIG. 3, is generated.
The conventional deck 100 as shown in FIG. 1 employs a separate support 171 (FIG. 1) to prevent the movement of the pole base assembly 160 (FIG. 1) due to the tension of the magnetic tape and the moment as mentioned above. More specifically, the support 171 is formed on the head drum base 170 and supports the pole base assembly 160 by contact when the loading of the magnetic tape is completed. However, in the conventional deck 200 shown in FIG. 2, as the stationary guide rails 281 are formed by bending a part of the main chassis 210, the support 171 as shown in FIG. 1 is omitted. Accordingly, as shown in FIG. 3, movement of the pole base assembly 260 by the tension of the magnetic tape and the moment cannot be prevented in the deck 200 of FIG. 2, and as a result, the running of the magnetic tape cannot be guided stably.
Additionally, there is a movement gap G defined between the link member 268, and the guide rails 281, 285, to ensure that contact between the link member 268 and the guide rails 281, 285 does not occur during the movement of the pole base assembly 260, and the pole base assembly 260 can be moved smoothly. However, because one side of the pole base assembly 260 is pressed by the link member 268 to move, a moment to pivot the pole base assembly 260 about its center occurs, and as a result, the pole base assembly 260 is moved as much as the gap G allows.